High-performance MALDI-TOF MS for Peptides and Small Molecules Summary. This project will build on recent advances in MALDI-TOF mass spectrometry to develop new instruments and software that provide resolving power and mass accuracy competitive with electrospray ionization on FTICR and Orbitrap instruments, but with speed, throughput, sensitivity and dynamic range orders of magnitude greater than are possible with any electrospray system. In preliminary work a prototype instrument has been developed that provides greater than 30,000 resolving power at a selected mass, and ppm mass accuracy over a broad mass range on known protein digests. Based on preliminary results and theoretical calculations the ultimate resolving power is expected to be at least 100,000 in a small, inexpensive benchtop instrument with better than 1ppm RMS mass accuracy for all spots on a large format MALDI plate using automated internal calibration with no operator intervention and sensitivity to detect and accurately determine masses at the 1 attomole level. The long-range goal of this project is to provide practical commercial instruments that make the full power of high-performance MALDI-TOF mass spectrometry routinely available for difficult biological applications that are not satisfactorily served by the tools presently available. This effort will include technical advances in TOF MS and will also focus on the needs of specific applications and on developing reliable and cost-effective means for satisfying these needs. PUBLIC HEALTH RELEVANCE: The proposed instrument is a vital component of new integrated analytical systems based on MALDI that will make large-scale proteomics and metabolomics practical. Completion of the human genome project and improved methods for analyzing proteins and small molecules in complex biological samples have been widely predicted to dramatically change drug discovery and clinical practice of medicine in the near future, but this has not yet been realized. Current technology is clearly not up to the task.